One-Step Hydrothermal Crystallization of a Layered Double Hydroxide/Alumina Bilayer Film on Aluminum and Its Corrosion Resistance Properties

Abstract

A zinc-aluminum layered double hydroxide (ZnAl-LDH)/alumina bilayer film has been fabricated on an aluminum substrate by a one-step hydrothermal crystallization method. The LDH film was uniform and compact. XRD patterns and SEM images showed that the LDH film was highly oriented with the c-axis of the crystallites parallel to the substrate surface. The alumina layer existing between the LDH film and the substrate was formed prior to the LDH during the crystallization process. Polarization measurements showed that the bilayer film exhibited a low corrosion current density value of 10(-8) A/cm(2), which means that the LDH/alumina bilayer film can effectively protect aluminum from corrosion. Electrochemical impedance spectroscopy (EIS) showed that the impedance of the bilayer was 16 MOmega, meaning that the film served as a passive layer with a high charge transfer resistance. The adhesion between the film and the substrate was very strong which enhances its potential for practical application.

Superhydrophobic surfaces for corrosion protection: a review of recent progresses and future directions

“…53,54 Hydrothermal method Similar to the two methods above, the hydrothermal method is another important top-down approach for fabrication of superhydrophobic anticorrosive surfaces. [55][56][57][58][59][60][61] Here, the surface microstructures are synthesized from an aqueous environment under elevated heat and/or pressure. Hydrothermal methods are considered more environmentally friendly since the chemical used to create surface microstructures is only H 2 O or dilute H 2 O 2 .…”

Characteristics, Preparation Routes and Metallurgical Applications of LDHs: An Overview

“…It is still a one-step recipe that guarantees quite a good adhesion and morphology [30][31][32]. Instead of adopting dissolved metal salts, one of the two metals is provided as a substrate, which behaves either as a sacrificing element for the film growing on it, or a reacting source of one of the corresponding metal.…”

“…Corrosion of magnesium alloys is a critical issue for their industrial applications on a large scale. Zeng et al [125] prepared nano-sized ZnAl-LDHs coating by co-precipitation and hydrothermal method on AZ 31 Mg alloy, and in order to prolong the service life of the ZnAl-LDH coating, a a polylactic acid (PLA) coating was sealed on the top layer of the coating using a vacuum freeze-drying method.…”

“…The ZnAl-LDH coating was synthesized by the combination of the co-precipitation and the hydrothermal process on AZ 31 Mg alloy. It exhibits two layers, namely a compact inner layer and porous outer layer.…”

Effect of surfactant alkyl chain length on the dispersion, and thermal and dynamic mechanical properties of LDPE/organo-LDH composites

“…As layered hosts, LDHs have been used in many potential applications, such as catalysts, ceramic precursors, ion exchangers, absorbents, medicine stabilizers, and for controlled release of anions [6][7][8][9][10][11][12][13]. Very recently, their potential as nanofillers for preparing polymer nanocomposites has received considerable attention from both academic and industrial points of view.…”